Removal methods of rigid stylets to minimise adverse force and tracheal tube movement: a mathematical and in-vitro analysis in manikins

This study investigated displacement of the tracheal tube caused by different methods of intubating stylet removal, using in-vitro experiments and mathematical analysis. In the first in-vitro experiment, we measured the distance travelled by the tube tip during stylet extraction. Then, we investigated the ideal technique for stylet extraction using mathematical analysis, which would cause minimal tube displacement. Then, using a training manikin, we measured the force applied to the vocal cords and stylet extraction force during tracheal intubation. When the stylet was extracted along a straight path towards the stylet end, the distance travelled by the tube tip significantly increased as the bending angle increased. Mathematical analysis revealed that the stylet should be diagonally extracted (in the sagittal plane) at an appropriate angle, rather than along a straight path towards the direction of the stylet end. In simulated tracheal intubation, extraction force and force applied to the vocal cords both significantly increased as the bending angle increased. Compared with the ‘hockey stick’-shaped stylet, the arcuate-shaped stylet resulted in reduced force. Our results indicate the potential risk for vocal cord injury when using hockey stick-shaped stylets with large bending angles.     

Assessment and management of the predicted difficult airway in babies and children

Although it is essential to take a history and examine every child prior to airway management, preoperative anticipation of a difficult airway is not totally reliable and therefore it is wise to be prepared for the unexpected difficult airway. Information about the airway can be gained from previous medical records, current history, physical examination and other tests. A natural consequence of airway assessment is development of an airway plan. Important anatomical and physiological features may be identified in an airway assessment which can then have a direct influence on the subsequent airway plan. Managing the predicted difficult airway is usually elective. This allows proper preparation of equipment, assistants, expertise and the environment required for the airway plan. This article will discuss paediatric airway assessment, outline those features that contribute to airway difficulty, and identify indications and risk factors associated with various airway techniques. Key objectives for an airway management plan are to maintain oxygenation and avoid trauma. This involves adopting techniques that avoid hypoxia and provide a high success rate with minimum attempts.     

Tips and tricks to increase the success rate of blind tracheal intubation through the Air-Q™ versus the intubating laryngeal mask airway Fastrach™

BackgroundThe Air-Q intubating laryngeal airway is a new supraglottic airway device which overcomes some of the limitations inherent to the intubating laryngeal mask airway (ILMA Fastrach^™) for tracheal intubation. Previous studies showed lower success rate of the Air-Q^™ versus ILMA Fastrach^™. This study was conducted to illustrate new maneuvers for increasing the success rate of Air-Q^™ versus ILMA Fastrach^™ and compare between both devices.MethodsOne-hundred and seventy adult patients, ASA I or II, aged >16 years old undergoing elective surgery under general anesthesia were divided randomly into 2 equal groups (85 each). Group A: using Air-Q ILA size 3.5 or size 4.5 Group B: using ILMA size 4 or size 5 according to the manufacturer’s recommendations for body weight in both groups. The time and the total success rate of blind intubation through them in 2 attempts only were recorded. In Group A, extension of the head with cricoid pressure was applied. The hemodynamic response to devices insertion and the complications related to both devices were compared.ResultsIn Group A, the total success rate in 2 attempts was 94.12%, while in Group B, it was 96.47%. However, this difference was not statistically significant. The first attempt success rate was 81.18% in Group A, while it was 82.35% in Group B. The total time to intubate the hemodynamic response to device insertion and the incidence of complications (sore throat, trauma and hoarseness of voice) showed no statistically significant difference between both groups.ConclusionThis study showed that extension of the head with cricoid pressure greatly increases the success rate of blind intubation through the Air-Q to 94.12% versus the ILMA Fastrach 96.47% with no statistically significant difference between both devices.     

序贯性建立人工气道在重症脑损伤患者救治中的应用

目的探讨序贯性建立人工气道对重症脑损伤患者救治中的安全性的影响。方法选取2010-04-2014-03入住重症医学科(ICU)时APACHE-Ⅱ评分≥15分、4分≤GCS≤8分、ICU住院时间≥3d、估计气管插管超过3~7d者的重症脑损伤患者44例,随机分为2组,分别按不同方法实施气道开放,试验组采用序贯气道开放法,即在气管切开导管置入气管内之前仍保留气管插管,待气切导管完全正确放置,再拔除气管插管,全过程始终使用呼吸机辅助通气,常规组在气管切开造口过程中不使用呼吸机辅助通气,仅吸氧4~8L/min;观察2组患者的操作时间、APACHE-Ⅱ评分、生命体征、术后24h NSE水平、血气分析以及随访3个月的GOS评分。结果 (1)2组患者入科时、气管切开术前APACHE-Ⅱ、HR、RR、Bp、SpO2比较差异无统计学意义(P0.05);气管切开造口术后与入科时APACHE-Ⅱ、SpO2相比差异均有统计学意义(P0.05);同时气管切开术后APACHE-Ⅱ、HR、RR、Bp、SpO2在2组患者间的差异均有统计学意义(P0.05)。(2)2组患者入科时以及气管切开前血气分析中的pH、PaO2、PaCO2和术后NSE水平差异均无统计学意义(P0.05);气管切开造口术后与入科时相比升高,差异有统计学意义(P0.05);对比2组患者的气管切开术后pH、PaO2、PaCO2和术后NSE水平差异具有统计学意义(P0.05)。(3)2组患者3个月后生存质量相比差异有统计学意义(P0.05)。结论重症脑损伤患者因长期呼吸机辅助通气,采取序贯性人工气道开放法能确保其安全性,改善预后,提高抢救成功率。     

脑室外引流术后并发颅内感染影响因素分析

目的：探讨脑室外引流术后并发颅内感染的影响因素。方法对105例经额脑室前角穿刺脑室外引流术患者的临床资料进行回顾性分析。结果在排除年龄、性别、手术耗时等干扰因素的情况下：（1）置管时间＞10 d者颅内感染率最高（16．0％），其次是≥7 d者（12．5％），＜7 d者最低（10．0％）。（2）单侧外引流颅内感染率低于双侧外引流（10．5％/16．7％）。（3）引流管在原切口的颅内感染率最高（23．1％），距原切口3 cm-5 cm的感染率最低（9．5％）。（4）未预防性应用抗生素的感染率最高（10．7％），术后3d鞘内注射感染率最低（4．5％）。结论脑室外引流术后并发颅内感染受影响因素众多，对患者进行全面的观察和治疗，可有效避免或减少颅内感染的发生。     

院前急救使用气管插管和球囊面罩的效果对比

目的探究在院前心脏停搏患者应用气管插管和球囊辅助呼吸进行急救的效果。方法选自本院2010年²012年进行院前急救的心脏停搏患者共50例,以随机的方式分为对照组与观察组,每组各有患者25例。对照组患者接受气管插管辅助呼吸,观察组患者接受球囊人工通气治疗。对比2组患者的各项临床指标。结果相对于对照组患者,观察组患者在建立通气时间方面有显著优越性,二者对比具有统计学意义(P<0.05);其余各项临床指标对比无统计学意义(P>0.05)。结论对心脏停搏患者进行院前急救的时候,应用球囊或者气管插管的急救方法,在临床效果对比方面相似,但是球囊辅助呼吸建立通气的时间要比气管插管短很多。     

Identification of the difficult airway

Nearly all patients who are seriously difficult to manage are easily identified because they have grossly obvious abnormalities. Conversely, it is difficult to identify the few normal-looking patients that are difficult to manage.     

Alternative techniques for tracheal intubation

Alternative rigid blade intubation devices available in recent years include the Glidescope, Airtraq and Bonfils laryngoscopes. The Macintosh blade works by displacing the tongue to one side and into the submandibular space while the tip of the device sits in the vallecula lifting the hyoid and so the epiglottis forward to reveal the laryngeal inlet. Under less favourable intubating conditions, the tongue is not accommodated in the submandibular space and tends to be compressed downwards. As a result the vallecula is not accessible and the blade tip is less able to be drawn forward. The retro-molar Bonfils avoids this problem by starting from a posterior position in the mouth and approaching the larynx below and alongside the tongue. The Bonfils also serves as a rigid stylet inside the tracheal tube again producing minimal tongue displacement. Airtraq also compresses the tongue less and usually sits on the posterior pharyngeal wall where it maintains the laryngeal view with a minimum of effort. It houses the tracheal tube in a channel that delivers it into the device's field of view. While better optical systems have tended to improve visualization of the laryngeal inlet, this has not necessarily resulted in easier intubation conditions, shorter intubation times or improved overall success rates. Part of the problem has been that they have limited fields of view compared with the stereoscopic view of tube advancement down to the larynx as afforded by Macintosh.     

术前不同CT测量方式对指导双腔支气管插管效果的影响

目的探讨CT平扫及重建分别应用于指导患者双腔支气管插管的效果,并分析气管内径与患者一般资料的相关性。方法选择2015年6月至2018年6月于我院行择期肺叶切除的患者53例,按照随机数字表法分为平扫组(n=27)和重建组(n=26),两组患者均于麻醉前行CT检查支气管情况,平扫组采用CT平扫法进行测量,而重建组则采用CT重建法进行测量,而后根据测量结果行双腔支气管插管。比较两组患者导管合适程度评价指标情况,插管并发症之间的差异。对患者通过重建测量出的气管内径与其身高、体重、年龄和BMI等一般资料进行相关性分析。结果重建组LT1、PT1及APP显著低于平扫组,插管1次成功率显著高于平扫组(P<0.05),重建组患者插管并发症总发生率显著低于平扫组(P<0.05);重建组胸廓入口处、主动脉弓处以及气管最狭窄处气管内径值显著高于平扫组(P<0.05);Pearson相关分析显示,身高与气管四个位置的内径呈正相关(P<0.05)。结论CT重建应用于指导双腔支气管导管型号的选择,能有效提升术前气管导管选择型号合适程度,并有效减少插管并发症;患者身高与气管内径呈显著正相关。